Cushioning material for forming press

Abstract

A cushioning material for forming press includes fiber material layers 31 and 32 superimposed with a bonding material layer 30 interposed, an upper rubber layer 33 positioned on an upper surface of one fiber material layer 31, a lower rubber layer 34 positioned on a lower surface of the other fiber material layer 32, an upper exudation preventing layer 35 positioned on an upper surface of the upper rubber layer 33, and a lower exudation preventing layer 36 positioned on a lower surface of the lower rubber layer 34.

What is claimed is:  
     
       1. A cushioning pad used for manufacturing a laminate by a hot press and interposed between the entire surface of the laminate and a heating platen in order to apply uniform pressure and heat to the entire surface of the laminate to be pressed, comprising: 
       (a) two or more fiber material layers, said layers comprising non-woven fabric, a woven fabric, or paper;  
       (b) a bonding material layer positioned between each of the fiber material layers for bonding upper and lower fiber material layers;  
       (c) an upper rubber layer positioned on an upper surface of the uppermost of said fiber material layers, and  
       (d) a lower rubber layer positioned on a lower surface of the lowermost of said fiber material layers, said upper and lower rubber layers being so constituted that weight loss of ten percent (10%) by thermal decomposition occurs at a temperature of at least 380° C., and  
       (e) an upper releasing layer positioned on an upper surface of the upper rubber layer for preventing exudation of a compounding agent contained in the upper rubber layer, said layers being adhered without any adhesive agent layer; and  
       (f) a lower releasing layer positioned on a lower surface of the lower rubber layer for preventing exudation of a compounding agent contained in the lower rubber layer, said layers being adhered without any adhesive agent layer,  
       said releasing layers (e) and (f) being selected from the group consisting of synthetic resin film, metal film, woven fabric, and paper.  
     
     
       2. The cushioning pad according to  claim 1 , wherein 
       all the fiber material layers are formed of a same material.  
     
     
       3. The cushioning pad according to  claim 1 , wherein 
       one, two or more said fiber material layers are formed of a material different from a material of remaining said fiber material layer.  
     
     
       4. The cushioning pad according to  claim 1 , wherein 
       the bonding material layer has an adhesive agent.  
     
     
       5. The cushioning pad according to  claim 1 , wherein 
       the bonding material layer comprises (i) a base material sheet resistant to deformation in a planar direction when subjected to heat or pressure, and (ii) an adhesive agent applied to opposing surfaces of the base material sheet.  
     
     
       6. The cushioning pad according to  claim 1 , wherein 
       the bonding material layer is a rubber sheet.  
     
     
       7. The cushioning pad according to  claim 6 , wherein 
       the bonding material layer is a rubber sheet in which a reinforcing woven fabric is embedded.  
     
     
       8. The cushioning pad according to  claim 1 , wherein 
       said fiber material is a non-woven fabric,  
       the bonding material layer is a foundation fabric with meshes, and  
       said non-woven fabric and said foundation fabric are bonded by tangling between fibers and the meshes of the foundation fabric caused by needle punching.  
     
     
       9. The cushioning pad according to  claim 8 , wherein 
       an adhesive agent is applied to the foundation fabric, and  
       said non-woven fabric and said foundation fabric are bonded by tangling between fibers and the meshes of the foundation fabric caused by needle punching as well as by adhesion by the adhesive agent.  
     
     
       10. The cushioning pad according to  claim 1 , wherein 
       the bonding material layer includes a first bonding material layer and a second bonding material layer;  
       the fiber material layer is a non-woven fabric;  
       the first bonding material layer is a foundation fabric with meshes;  
       said non-woven fabric and said foundation fabric are bonded by tangling between fibers and the meshes of the foundation fabric caused by needle punching;  
       the second bonding material layer has an adhesive agent; and  
       said cushioning material being prepared by laminating by means of the second bonding material layer, multiple stages of bonded non-woven fabric layers each prepared by bonding two or more said non-woven fabric layers by said first bonding material layer.  
     
     
       11. The cushioning pad according to  claim 10 , wherein 
       the second bonding material layer has a base material having a deformation in a planar direction when subjected to heat or pressure, and an adhesive agent applied to opposing surfaces of the base material sheet.  
     
     
       12. The cushioning pad according to  claim 10 , wherein 
       an adhesive agent is applied to the foundation fabric of the first bonding material layer; and  
       said non-woven fabric and said foundation fabric are bonded by tangling between fibers and the foundation fabric caused by needle punching as well as by adhesion by the adhesive agent.  
     
     
       13. The cushioning pad according to  claim 4 , wherein 
       said adhesive agent is a fluoroelastomer adhesive agent.  
     
     
       14. The cushioning pad according to  claim 4 , wherein 
       said adhesive agent is an EPDM adhesive agent.  
     
     
       15. The cushioning pad according to  claim 1 , wherein 
       the fiber material layer includes a fiber of which glass transition temperature is at least 200° C. and of which temperature at which weight loss of 10% is caused by thermal decomposition is at least 400° C.  
     
     
       16. The cushioning pad according to  claim 1 , wherein 
       an acrylic monomer is added to a composition forming the upper and the lower rubber layers.  
     
     
       17. The cushioning pad according to  claim 1 , wherein 
       a main component of the upper and lower rubber layers is a fluoroelastomer.  
     
     
       18. The cushioning pad according to  claim 1 , wherein 
       a main component of the upper and lower rubber layers is an EPDM.  
     
     
       19. The cushioning pad according to  claim 1 , wherein 
       the upper and the lower rubber layers are rubber coatings applied to rear surfaces of the releasing layers.  
     
     
       20. The cushioning pad according to  claim 1 , wherein 
       the exudation preventing layer is prepared by applying a resin selected from the group consisting of polyimide resin, fluoride resin, melamine resin and acryl resin, to a surface of a base material selected from the group consisting of a woven fabric and paper.  
     
     
       21. The cushioning pad according to  claim 1 , wherein 
       the exudation preventing layer is a fluoride resin film.